Current biomarkers of prostate cancer

Prostate cancer is one of the most common malignancies in men. Early detection of prostate cancer is largely determined by the widely used prostate specific antigen (PSA) blood test. However, as a diagnostic and prognostic test of prostate cancer, PSA has limited specificity, sensitivity and leads to hyper or underdiagnosis, which, in turn, can lead to excessive treatment. There fore, it is very important to develop diagnostic markers that can be used to determine prostate cancer at an early stage of development, assess the possible progression of the disease and prescribe optimal therapy. Significant progress has been made in the discovery of biomarkers for prostate cancer. For example, biomarkers such as %-free PSA, Prostate Health Index (PHI) or 4K score can be used to increase specificity and reduce the number of unnecessary biopsies, while the PCA3 test can be used to reduce the number of repeated biopsies in men with previously negative biopsy. To determine aggressiveness and predict the outcome of the disease, tissue multigenic tests can be used, such as: T2-ERG, ExoDx, SelectMDx and ConfirmMDx, Prolaris, Oncoytype DX, Decipher. The development of such diagnostic tests opens up new opportunities for improving the diagnosis of prostate cancer, prognosis and decision-making on the appointment of therapy. And with the increase in their availability, finally, the possibility of an individual approach to the appointment of treatment for men with prostate cancer appears on the horizon. This review paper presents the data on the most advanced diagnostic biomarkers of prostate cancer.

Combining prostate health index and multiparametric magnetic resonance imaging in estimating the histological diameter of prostate cancer

Background Although multiparametric magnetic resonance imaging (mpMRI) is widely used to assess the volume of prostate cancer, it often underestimates the histological tumor boundary. The aim of this study was to evaluate the feasibility of combining prostate health index (PHI) and mpMRI to estimate the histological tumor diameter and determine the safety margin during treatment of prostate cancer. Methods We retrospectively enrolled 72 prostate cancer patients who underwent radical prostatectomy and had received PHI tests and mpMRI before surgery. We compared the discrepancy between histological and radiological tumor diameter stratified by Prostate Imaging-Reporting and Data System (PI-RADS) score, and then assessed the influence of PHI on the discrepancy between low PI-RADS (2 or 3) and high PI-RADS (4 or 5) groups. Results The mean radiological and histological tumor diameters were 1.60 cm and 2.13 cm, respectively. The median discrepancy between radiological and histological tumor diameter of PI-RADS 4 or 5 lesions was significantly greater than that of PI-RADS 2 or 3 lesions (0.50 cm, IQR (0.00–0.90) vs. 0.00 cm, IQR (−0.10–0.20), p = 0.02). In the low PI-RADS group, the upper limit of the discrepancy was 0.2 cm; so the safety margin could be set at 0.1 cm. In the high PI-RADS group, the upper limits of the discrepancy were 1.2, 1.6, and 2.2 cm in men with PHI < 30, 30–60, and > 60; so the safety margin could be set at 0.6, 0.8, and 1.1 cm, respectively. Conclusions Radiological tumor diameter on mpMRI often underestimated the histological tumor diameter, especially for PI-RADS 4 or 5 lesions. Combining mpMRI and PHI may help to better estimate the histological tumor diameter.

Prostate Health Index Density Outperforms Prostate Health Index in Clinically Significant Prostate Cancer Detection

BackgroundProstate-specific antigen (PSA) is considered neither sensitive nor specific for prostate cancer (PCa). We aimed to compare total PSA (tPSA), percentage of free PSA (%fPSA), the PSA density (PSAD), Prostate Health Index (PHI), and the PHI density (PHID) to see which one could best predict clinically significant prostate cancer (csPCa): a potentially lethal disease.MethodsA total of 412 men with PSA of 2–20 ng/mL were prospectively included. Serum biomarkers for PCa was collected before transrectal ultrasound guided prostate biopsy. PHI was calculated by the formula: (p2PSA/fPSA) x √tPSA. PHID was calculated as PHI divided by prostate volume measured by transrectal ultrasound.ResultsOf the 412 men, 134 (32.5%) and 94(22.8%) were diagnosed with PCa and csPCa, respectively. We used the area under the receiver operating characteristic curve (AUC) and decision curve analyses (DCA) to compare the performance of PSA related parameters, PHI and PHID in diagnosing csPCa. AUC for tPSA, %fPSA, %p2PSA, PSAD, PHI and PHID were 0.56、0.63、0.76、0.74、0.77 and 0.82 respectively for csPCa detection. In the univariate analysis, the prostate volume, tPSA, %fPSA, %p2PSA, PHI, PSAD, and PHID were all significantly associated with csPCa, and PHID was the most important predictor (OR 1.41, 95% CI 1.15–1.72). Besides, The AUC of PHID was significantly larger than PHI in csPCa diagnosis (p=0.004). At 90% sensitivity, PHID had the highest specificity (54.1%) for csPCa and could reduce the most unnecessary biopsies (43.7%) and miss the fewest csPCa (8.5%) when PHID ≥ 0.67. In addition to AUC, DCA re-confirmed the clinical benefit of PHID over all PSA-related parameters and PHI in csPCa diagnosis. The PHID cut-off value was positively correlated with the csPCa ratio in the PHID risk table, which is useful for evaluating csPCa risk in a clinical setting.ConclusionThe PHID is an excellent predictor of csPCa. The PHID risk table may be used in standard clinical practice to pre-select men at the highest risk of harboring csPCa.

Prostate Health Index and Multiparametric MRI: Partners in Crime Fighting Overdiagnosis and Overtreatment in Prostate Cancer

Widespread use of PSA as the standard tool for prostate cancer (PCa) diagnosis led to a high rate of overdiagnosis and overtreatment. In this study, we evaluated the performance of the prostate health index (PHI) and multiparametric magnetic resonance imaging (mpMRI) for the prediction of positive biopsy and of high-grade PCa at radical prostatectomy (RP). To this end, we prospectively enrolled 196 biopsy-naïve patients who underwent mpMRI. A subgroup of 116 subjects with biopsy-proven PCa underwent surgery. We found that PHI significantly outperformed both PI-RADS score (difference in AUC: 0.14; p < 0.001) and PHI density (difference in AUC: 0.08; p = 0.002) in the ability to predict positive biopsy with a cut-off value of 42.7 as the best threshold. Conversely, comparing the performance in the identification of clinically significant prostate cancer (csPCa) at RP, we found that PHI ≥61.68 and PI-RADS score ≥4 were able to identify csPCa (Gleason score ≥7 (3 + 4)) both alone and added to a base model including age, PSA, fPSA-to-tPSA ratio and prostate volume. In conclusion, PHI had a better ability than PI-RADS score to predict positive biopsy, whereas it had a comparable performance in the identification of pathological csPCa.

Usefulness of the prostate health index in predicting the presence and aggressiveness of prostate cancer among Korean men: a prospective observational study

Background We aimed to evaluate the usefulness of the Beckman Coulter prostate health index (PHI) and to compare it with total prostate-specific antigen (PSA) levels and related derivatives in predicting the presence and aggressiveness of prostate cancer (PCa) in the Korean population. Methods A total of 140 men who underwent their first prostate biopsy for suspected PCa were included in this prospective observational study. The diagnostic performance of total PSA, free PSA, %free PSA, [–2] proPSA (p2PSA), %p2PSA, and PHI in detecting and predicting the aggressiveness of PCa was estimated using the receiver operating characteristic curve (ROC) and logistic multivariate regression analyses. Results Of 140 patients, PCa was detected in 63 (45%) of participants, and 48 (76.2%) of them had significant cancer with a Gleason score (GS) ≥ 7. In the whole group, the area under the curve (AUC) for ROC analysis of tPSA, free PSA, %fPSA, p2PSA, %p2PSA, and PHI were 0.63, 0.57, 0.69, 0.69, 0.72, and 0.76, respectively, and the AUC was significantly greater in the PHI group than in the tPSA group (p = 0.005). For PCa with GS ≥ 7, the AUCs for tPSA, free PSA, %fPSA, p2PSA, %p2PSA, and PHI were 0.62, 0.58, 0.41, 0.79, 0.86, and 0.87, respectively, and the AUC was significantly greater in the PHI group than in the tPSA group (p < 0.001). In the subgroup with tPSA 4–10 ng/mL, both %p2PSA and PHI were strong independent predictors for PCa (p = 0.007, p = 0.006) and significantly improved the predictive accuracy of a base multivariable model, including age, tPSA, fPSA and %fPSA, using multivariate logistic regression analysis. (p = 0.054, p = 0.048). Additionally, at a cutoff PHI value > 33.4, 22.9% (32/140) of biopsies could be avoided without missing any cases of aggressive cancer. Conclusions This study shows that %p2PSA and PHI are superior to total PSA and %fPSA in predicting the presence and aggressiveness (GS ≥ 7) of PCa among Korean men. Using PHI, a significant proportion of unnecessary biopsies can be avoided.

1226 The Clinical Utility of Prostate Health Index Density in The Diagnosis of Clinically Significant Prostate Cancer: A Systematic Review

Aim Prostate health index (PHI) is a diagnostic test for prostate cancer that combines free prostate specific antigen (PSA), total PSA and [-2]proPSA. PHI has been shown to be more accurate than PSA testing at detecting prostate cancer and its use has been shown to reduce unnecessary prostate biopsies. Prostate health index density (PHID), derived by dividing PHI by prostate volume, has been suggested as a more accurate test compared to standard PHI by several authors. The aim of this systematic review was to evaluate the diagnostic accuracy of PHID for clinically significant prostate cancer, identify an optimal diagnostic threshold and assess the clinical utility of PHID as a novel diagnostic test for prostate cancer. Method A systematic review of primary studies was conducted. Medline, Embase, Scopus and Cochrane databases were searched with key terms. Results were screened and full papers reviewed by two reviewers with pre-determined inclusion criteria. QUADAS-2 was used for quality appraisal. Data analysis was conducted in line with PRISMA guidelines. Results Nine studies were included. Quality appraisal revealed a high degree of heterogeneity between studies. PHID thresholds ranged 0.32-1.38. PHID had an area under the curve value of 0.59-0.9 and negative predictive value of 81-100% for clinically significant disease. PHID outperformed PHI in three studies, but this was not replicated in the other studies. Conclusions This systematic review found PHID did not consistently outperform PHI. PHID was found to have low clinical utility in the diagnosis of prostate cancer based on the available evidence, with further research warranted.